Female slaves, Wives beating - explicit so called Religious texts

               Quran
Quran (4:34) - "Men are the maintainers of women because Allah has made some of them to excel others and because they spend out of their property; the good women are therefore obedient, guarding the unseen as Allah has guarded; and (as to) those on whose part you fear desertion, admonish them, and leave them alone in the sleeping-places and beat them; then if they obey you, do not seek a way against them; surely Allah is High, Great."  Contemporary translations sometimes water down the word 'beat', but it is the same one used in verse  8:12 and clearly means 'to strike'.
Quran (38:44) - "And take in your hand a green branch and beat her with it, and do not break your oath..."  Allah telling Job to beat his wife (Tafsir).
 

Hadith and Sira
Bukhari (72:715) - A woman came to Muhammad and begged her to stop her husband from beating her. Her skin was bruised so badly that it is described as being "greener" than the green veil she was wearing. Muhammad did not admonish her husband, but instead ordered her to return to him and submit to his sexual desires.

 Bukhari (72:715) - "Aisha said, 'I have not seen any woman suffering as much as the believing women'" Muhammad's own wife complained of the abuse that the women of her religion suffered relative to other women.

 Muslim (4:2127) - Muhammad struck his favorite wife, Aisha, in the chest one evening when she left the house without his permission. Aisha narrates,  "He struck me on the chest which caused me pain."

 Muslim (9:3506) - Muhammad's fathers-in-law (Abu Bakr and Umar) amused him by slapping his wives (Aisha and Hafsa) for annoying him. According to the Hadith, the prophet of Islam laughed upon hearing this.

 Abu Dawud (2141) - "Iyas bin ‘Abd Allah bin Abi Dhubab reported the Apostle of Allah (may peace be upon him) as saying: Do not beat Allah’s handmaidens, but when ‘Umar came to the Apostle of Allah (may peace be upon him) and said: Women have become emboldened towards their husbands, he (the Prophet) gave permission to beat them." At first, Muhammad forbade men from beating their wives, but he rescinded this once it was reported that women were becoming emboldened toward their husbands. Beatings in a Muslim marriage are sometimes necessary to keep women in their place.

 Abu Dawud (2142) - "The Prophet (peace be upon him) said: A man will not be asked as to why he beat his wife."

Abu Dawud (2126) -  "A man from the Ansar called Basrah said: 'I married a virgin woman in her veil. When I entered upon her, I found her pregnant. (I mentioned this to the Prophet).' The Prophet (peace_be_upon_him) said: 'She will get the dower, for you made her vagina lawful for you. The child will be your slave. When she has begotten (a child), flog her'" A Muslim thinks he is getting a virgin, then finds out that she is pregnant. Muhammad tells him to treat the woman as a sex slave and then flog her after she delivers the child.

Ibn Ishaq/Hisham 969 - Requires that a married woman be  "put in a separate room and beaten lightly" if she "act in a sexual manner toward others." According to the Hadith, this can be for an offense as petty as merely being alone with a man to whom she is not related.

Kash-shaf (the revealer) of al-Zamkhshari (Vol. 1, p. 525) - [Muhammad said] "Hang up your scourge where your wife can see it"


                Does Islam allow a man to hit his wife?

Yes, but only if she doesn't do as he asks. The beating must stop if the woman complies with her husband's demands. Behind verbal abuse and abandonment, beating is intended as last resort solution to coerce submission.
According her testimony in the Hadith, Muhammad physically struck his favorite wife for leaving the house without his permission. It is not known how he treated his less-favored wives.